Support out_start_interval to mark first out_sosi.sync interval.

libraries/base/dp/src/vhdl/dp_bsn_sync_scheduler.vhd

libraries/base/dp/src/vhdl/mmp_dp_bsn_sync_scheduler.vhd

libraries/base/dp/src/vhdl/mmp_dp_bsn_sync_scheduler_arr.vhd